Utilizing a previously identified population-based cohort of adults who developed JRA while living in Rochester, Minnesota, between January 1, 1960, and December 31, 1993, we plan to investigate the prevalence and severity of osteopenia in adults with a history of JRA. This will allow testing of the hypothesis that JRA-associated osteopenia persists into adulthood in a significant number of patients placing them at an increased fracture risk. The first specific aim of this study is to utilize dual-energy x-ray absorptiometry (DEXA) scanning to measure bone mineral densities in a cohort of adults with a history of JRA previously identified using the Rochester Epidemiology Project by 1) delineating the prevalence and severity of osteopenia in this population-based cohort of adults with a history of JRA, and 2) comparing bone loss in the appendicular and axial skeleton in this population of patients. The second specific aim is to apply regression analysis techniques in identifying predictors of osteopenia in adults with a history of JRA including age at diagnosis, gender, JRA subtype, Steinbroker functional class, ANA and rheumatoid factor status, steroid use, calcium intake, and exercise level.